Atrial pacing, the forgotten pacing mode.

In patients with sick sinus syndrome and normal atrioventricular conduction, physiological pacing can be accomplished with either a single chamber atrial pacemaker AAI/R or a dual chamber pacemaker DDD/R. The single chamber device has the advantages of simpler implantation and lower initial costs, while the dual chamber device offers protection in case atrioventricular conduction disturbances develop in the future. When rigorous attention is paid to the pre-implantation selection criteria, the incidence of reported second- or third-degree atrioventricular block varied between 0.4 and 1.8% per annum. Medical practice, however, has shifted to predominant implantation of DDD/R pacemakers in more than 95% of patients with sick sinus syndrome. Recent publications have reported an increase in left atrial diameter, decrease in left ventricular fractional shortening and increased incidence of atrial fibrillation in patients with DDD/R pacing as compared with patients with single chamber atrial devices. These changes were proportional to the percentage of ventricular paced beats.New algorithms in dual chamber devices have been developed in order to minimise ventricular stimulation. These are being evaluated at present. In my opinion there is still a place for atrial pacing in selected patients with sick sinus syndrome with a minimum risk of developing complete atrioventricular block. (Neth Heart J 2008;16(Suppl1):S25-S27.).

Prevalence and risk factors of gallstone disease in a high altitude Saudi population.

To study the prevalence of gallstone disease and related risk factors in a Saudi Arabian population a cross-sectional community-based study was made of 291 people from Abha district, Asir region. A structured interview collected background data and all participants had upper abdominal ultrasonography to detect gallstones. The overall prevalence of gallstone disease was 11.7%. Using logistic regression multivariate analysis, the following were significant risk factors for gallstone disease: female sex, family history of gallstone disease and past history of pancreatitis. Age, education, blood pressure, smoking, coffee intake, overweight, diabetes mellitus, number of pregnancies and use of oral contraceptives were not significant risk factors. Discriminant analysis of symptoms showed that only right hypochondrium pain was significantly associated with gallstone disease.

Primary health care emergency services in Abha district of southwestern Saudi Arabia.

To study emergency services delivery in all 30 primary health care centres in Abha district of Asir region, Saudi Arabia, data were collected about equipment and facilities, physicians' practices and attitudes, and patients' utilization of and satisfaction with emergency services. Two centres had no devoted place for emergency services. Lack of some essential equipment and drugs was evident. The greatest continuing medical education need for doctors was the management of cardiovascular emergencies (72.3%). Many doctors (40.4%) did not consider the majority of cases as true emergencies. Many patients (43.7%) used the centres for emergency services, the most common being trauma, burns and orthopaedics (47.8%). Most patients were satisfied overall with emergency services (82.2%).

Prevalence and risk factors of gallstone disease in a high altitude Saudi population

To study the prevalence of gallstone disease and related risk factors in a Saudi Arabian population a cross-sectional community-based study was made of 291 people from Abha district, Asir region. A structured interview collected background data and all participants had upper abdominal ultrasonography to detect gallstones. The overall prevalence of gallstone disease was 11.7%. Using logistic regression multivariate analysis, the following were significant risk factors for gallstone disease: female sex, family history of gallstone disease and past history of pancreatitis. Age, education, blood pressure, smoking, coffee intake, overweight, diabetes mellitus, number of pregnancies and use of oral contraceptives were not significant risk factors. Discriminant analysis of symptoms showed that only right hypochondrium pain was significantly associated with gallstone disease

Primary health care emergency services in Abha district of southwestern Saudi Arabia

To study emergency services delivery in all 30 primary health care centres in Abha district of Asir region, Saudi Arabia, data were collected about equipment and facilities, physicians' practices and attitudes, and patients' utilization of and satisfaction with emergency services. Two centres had no devoted place for emergency services. Lack of some essential equipment and drugs was evident. The greatest continuing medical education need for doctors was the management of cardiovascular emergencies [72.3%]. Many doctors [40.4%] did not consider the majority of cases as true emergencies. Many patients [43.7%] used the centres for emergency services, the most common being trauma, burns and orthopaedics [47.8%]. Most patients were satisfied overall with emergency services [82.2%]

Primary health care services utilization and satisfaction among the elderly in Asir region, Saudi Arabia

Use of primary health care [PHC] services and satisfaction among elderly people [60 + years] in Asir was studied in 26 PHC centers. They visited PHC centers significantly less often than younger adults but they were referred significantly more often to secondary and tertiary care and for more laboratory tests. A r and om sample of 253 elderly people attending the centers was interviewed about accessibility, continuity, humaneness, informativeness and thoroughness of care. Overall, 79.0% were satisfied with the services provided. The leading 3 items of dissatisfaction were: not enough audiovisual means for health education [65.1%], long time spent in the centre [46.4%], and not enough specialty clinics [42.5%]

Arrhythmogenic right ventricular dysplasia and sudden cardiac death in endurance athletes.

Arrhythmogenic right ventricular dysplasia (ARVD) is a cardiomyopathy with several time-dependent clinical presentations. The clinical characteristics depend on the penetration grade of the disease. There are two different histological patterns consisting of a lipomatous and a fibrolipomatous form. The presence of arrhythmias in the ARVD syndrome constitutes an important risk factor for sudden cardiac death in athletes. In this article, we describe two professional endurance athletes who died suddenly. One of these athletes had asymptomatic ARVD, the other had symptomatic polymorphic ventricular tachycardias. Both athletes showed fatty penetration of the disease in both the right and left ventricle; one of them also showed fatty involvement at the atrial level and in the other there were signs of myocarditis consistent with ARVD. In the last few years magnetic resonance imaging has become an important diagnostic tool in patients with ARVD.

Congenital and Atherosclerotic (Acquired) Coronary Artery Aneurysms: Coronary Angiographic and Morphologic Observations in 10 Patients

Coronary angiographic observations in 10 patients with coronary artery aneurysms (CAAs) are reported. Four patients had atherosclerotic (acquired) and six had congenital CAAs. The mean age of patients with acquired CAAs was higher (64.7 years) compared with the congenital group (53.2 years). Ipsilateral myocardial infarction (MI) occurred in three of four patients with acquired CAAs but MI was not located on the same side as the aneurysm-bearing coronary artery (contralateral) in two patients with the congenital variety. In the patients with congenital CAAs, an aneurysm predilection site was observed in the proximal portion of the aneurysm-bearing vessel. Dual and multiple aneurysms were more common in the acquired CAAs. Although congenital CAAs were sizeable, the small-sized atherosclerotic CAAs developed complications more frequently. During an average follow-up of 7.9 years, only one patient died of a noncardiac cause and another developed recurrent uncomplicated non-Q wave lateral MI. Both subjects had atherosclerotic CAAs. In our series, no rupture or sudden death occurred. Coronary artery bypass grafting (CABG) was performed in three patients with acquired and in one patient with congenital CAAs. In the latter patient, simultaneous ligation of the congenital aneurysm associated with a coronary arteriovenous fistula was performed. Regarding antiplatelet and anticoagulant policy for the whole group, three patients were on aspirin, four were on acenocoumarol, and in another three subjects with congenital CAAs, a medical regimen was followed. Larger series, however, are required in order to elucidate further angiographic characteristics of acquired vs congenital CAAs.

Coronary arteriovenous fistulas: collective review and management of six new cases--changing etiology, presentation, and treatment strategy.

We considered it worthwhile to review the literature of the last decade (1985-1995) to answer the question whether the etiology and the clinical picture of coronary arteriovenous fistulas (CAVFs) have changed. Furthermore, new therapeutic modalities such as percutaneous transcatheter embolization have been developed. We tried to define the place of these techniques in the therapeutic arena. Clinical presentation and management of six patients with eight congenital CAVFs and 76 subjects with 96 congenital and acquire I CAVFs taken from a review of the recent literature are presented. Sixty-three review subjects (78%) were treated medically with one fatal case. Ligation of the fistula was achieved by surgical techniques in 10% of review subjects, while percutaneous transcatheter embolization (PTE) was performed in nine patients (12%). Percutaneous transcatheter embolization techniques are being increasingly used in the treatment of CAVFs. The etiology of CAVFs has a tendency to show alterations toward the acquired pathogenesis. In 64% of the review subjects the fistula was congenital in origin, and in 36% it had an acquired cause. Among the patients of the current review, the clinical presentations were 55% asymptomatic, 34% chest pain (anginal or atypical), and 13% congestive heart failure. The CAVFs of our six patients are all congenital in origin. In the current review, the clinical presentation showed a trend toward increasing chest complaints (34%) compared with the review (10%) published in the mid 1970s. This may be due to a higher mean age, and hence increased concurrent coronary artery disease due to aging compared with the review population of two decades ago.

Coronary stenting for failed angioplasty in acute myocardial infarction.

UNLABELLED: Intracoronary stents were implanted in 15 patients after unsuccessful PTCA in the setting of acute myocardial infarction (AMI). The stented vessel was the left anterior descending (LAD) in 11 patients, the right coronary artery (RCA) in 3 patients, and a venous bypass graft to the LAD in a single patient. A total of 16 stents were implanted (15 Palmaz Schatz, Johnson and Johnson; and 1 Wiktor, Medtronic). FOLLOW-UP: 1 patient died 10 days after stent implantation as a result of renal failure and cardiogenic shock. Subacute thrombosis occurred in 2 patients, 5 and 15 days after stent implantation; both underwent successful emergency coronary artery bypass grafting (CABG). The remaining 12 patients were free from major ischemic events (death, AMI, and further revascularization) after a mean follow-up of 18.7 +/- 4.1 months. We conclude that the long-term results of intracoronary stenting in AMI after failed PTCA are favourable.

Hydralazine-induced constrictive pericarditis.

A 59-year-old man was diagnosed as having constrictive pericarditis 17 months after a typical hydralazine-induced autoimmune syndrome. This late complication of hydralazine has been reported only once. Ten years later the patient was found to have anti-neutrophil cytoplasmic antibodies directed against myeloperoxidase.

Fractional flow reserve. A useful index to evaluate the influence of an epicardial coronary stenosis on myocardial blood flow.

BACKGROUND: Fractional flow reserve (FFR), defined as the ratio of maximum flow in the presence of a stenosis to normal maximum flow, is a lesion-specific index of stenosis severity that can be calculated by simultaneous measurement of mean arterial, distal coronary, and central venous pressure (Pa, Pd, and Pv, respectively), during pharmacological vasodilation. The aims of this study were to define ranges of FFR values, whether associated with inducible ischemia or not, and to investigate FFR in normal coronary arteries. METHODS AND RESULTS: In 60 patients accepted for percutaneous transluminal coronary angioplasty (PTCA) of single-vessel disease, with a positive exercise test (ET) < 24 hours before PTCA, FFR was determined during adenosine-induced hyperemia just before and 15 minutes after angioplasty. Pa was measured by the guiding catheter, Pd by an 0.018-in fiber-optic pressure-monitoring wire, and Pv, by a multipurpose catheter. The ET was repeated after 5 to 7 days, and only if this second ET had reverted to normal was the pre-PTCA value of FFR definitely considered to be associated with inducible ischemia and the post-PTCA value not. Myocardial FFR (FFRmyo) increased from 0.53 +/- 0.15 before PTCA to 0.88 +/- 0.07 after PTCA. Coronary FFR increased from 0.38 +/- 0.19 to 0.83 +/- 0.12. In all patients, values of FFRmyo definitely associated with ischemia were < or = 0.74, whereas all except two values not associated with inducible ischemia exceeded 0.74. Moreover, FFRmyo in 18 coronary arteries in 5 normal patients equaled 0.98 +/- 0.03. CONCLUSIONS: A value of FFRmyo of 0.74 reliably discriminates coronary stenosis, whether associated with inducible ischemia or not. Therefore, FFRmyo is a useful index to determine the functional significance of an epicardial coronary stenosis and may facilitate clinical decision making in patients with an equivocal coronary stenosis.

Quantification of recruitable coronary collateral blood flow in conscious humans and its potential to predict future ischemic events.

OBJECTIVES: The present study was designed to evaluate the applicability of a pressure-flow equation for quantitative calculation of recruitable collateral blood flow at coronary artery occlusion in conscious patients and to investigate the value of that index to predict future ischemic events. BACKGROUND: Recent experimental studies have indicated that recruitable collateral blood flow at coronary artery occlusion can be expressed as a fraction of normal maximal myocardial blood flow by simultaneous recordings of mean arterial, coronary wedge and central venous pressures, respectively. This index is called the pressure-derived fractional collateral flow and is independent of hemodynamic loading conditions. METHODS: In 120 patients undergoing elective coronary angioplasty, mean arterial, coronary wedge and central venous pressures were measured at balloon inflations of 2 min. All patients had a recent exercise electrocardiogram (ECG) with positive findings showing clearly distinguishable, reversible ECG abnormalities, enabling recognition of ischemia at balloon inflation. Fractional collateral blood flow at angioplasty was calculated by coronary wedge pressure minus central venous pressure divided by mean arterial pressure minus central venous pressure and correlated to the presence or absence of ischemia at balloon inflation. Ischemic events were monitored during a follow-up period of 6 to 22 months. RESULTS: In 90 of the 120 patients, ischemia was present at balloon inflation, and in 82 of these patients, fractional collateral blood flow was < or = 23%. By contrast, in 29 patients, no ischemia was present, and fractional collateral blood flow was > 24% in all 29. During the follow-up period, 16 patients had an ischemic event. Fifteen of these 16 patients were in the group with insufficient collateral flow (p < 0.05). CONCLUSIONS: To our knowledge, this study presents the first method for quantitative assessment of recruitable collateral blood flow in humans in the catheterization laboratory. Sufficient and insufficient collateral circulation can be reliably distinguished by this method. Use of this method can also help to provide more insight into the extent and behavior of the collateral circulation for investigational purposes and may have potential clinical implications.

Coronary angiographic morphology of congenital coronary arteriovenous fistulas in adults: report of four new cases and review of angiograms of fifteen reported cases.

The coronary angiographic features of four new cases of congenital coronary arteriovenous fistulas (CAVFs) are described, and the angiograms of 15 reported cases are reviewed. The morphologic appearance of CAVFs varied from a small discrete single channel to a highly complex plexiform network with a maze of fine vessels. The majority of CAVFs in our series were composed of a single channel. Aneurysmal formation was present in 26% (6/23). Aneurysmal formation involved only the pathway and/or the termination, but never originated from the beginning of the CAVFs.

P wave oversensing in a unipolar VVI pacemaker.

A 45-year-old male had a VVI pacemaker implanted 20 years ago because of complete heart block. Because of perforation of the lead the pulse generator was removed after 4 weeks and a second lead was implanted from the contralateral side. Recently, the patient presented with symptoms of lightheadedness and syncope associated with prolonged pauses in the electrocardiogram. From the ECG, the ECG interpretation channel, and intracardiac electrogram telemetry, it was concluded that the VVI pacemaker was inhibited by P waves. The most likely explanation for this phenomenon was an insulation defect in the functioning lead caused by friction with the abandoned lead at the level of the high right atrium.

Upper rate pacing after radiofrequency catheter ablation in a minute ventilation rate adaptive DDD pacemaker.

A 58-year-old man with an implanted minute ventilation rate adaptive DDD pacemaker underwent RF ablation of the AV junction because of symptomatic supraventricular tachyarrhythmias. Immediately after ablation, while the pacemaker was programmed in the DDDR mode, AV sequential pacing at upper rate was observed. After programming the pacing system to the DDD mode and repeated ablation, no abnormalities were observed. It was concluded that AV sequential upper rate pacing was caused by false interpretation of the RF current by the sensor measuring transthoracic impedance as an indicator for minute ventilation.

Experience with a 6 French double loop catheter for right coronary angiography.

A 6Fr double loop diagnostic catheter was developed for angiography of the right coronary artery and tested in 101 patients. Its primary use was employed in 60 patients, and after failure of a 6Fr right Judkins diagnostic catheter in 41 patients. Primary use was successful in 56 out of 60 patients (93%); four failures were cannulated with 6Fr right Judkins diagnostic catheters. After failure of 6Fr right Judkins diagnostic catheters, 36 out of 41 patients (88%) were successfully cannulated with 6Fr double loop diagnostic catheters. Causes of failure of 6Fr right Judkins diagnostic catheters were: inadequate torque control in 24 patients, because of tortuosity of femoro iliac arteries or aorta; dilatation of the ascending aorta, abnormal origin or course of the initial segment of the right coronary artery in 17 patients. Three out of five patients in whom right Judkins diagnostic and double loop diagnostic catheters failed to intubate the right coronary artery were successfully cannulated with 7Fr diagnostic catheters (right Judkins one patient; El Gamal one patient; right coronary bypass one patient). CONCLUSION. 6Fr double loop diagnostic catheters increased the success rate of right coronary angiography after failure of 6Fr right Judkins diagnostic catheters.

Characteristics of conditioned and sedentary men with acute coronary syndromes.

To evaluate the role of habitual exertion in the development and manifestation of coronary artery disease, 36 well-conditioned men with acute coronary syndromes (4 with unstable angina, 23 with acute myocardial infarction and 9 survivors of sudden ischemic death) related to sports were compared with 36 sedentary men with the same syndromes occurring at rest. The mean age of the study subjects was 48 years (range 25 to 65). Patients exercised on average 6 hours/week (range 2 to 15) for > or = 10 years (range 10 to 45). Coronary angiography was performed within 4 hours after the onset of symptoms. The well-conditioned men had fewer risk factors than the inactive men (control subjects): fewer of them smoked (58 vs 94%, odds ratio 0.08) or had serum total cholesterol levels > or = 240 mg/dl (14 vs 56%, odds ratio 0.13, both p < 0.05). In addition, these men had less diseased (28 vs 72%, odds ratio 0.15, p < 0.02) and less severely stenotic (36 vs 78%, odds ratio 0.16, p < 0.03) coronary arteries. The association between activity levels and angiographic disease severity remained significant after correction for risk factors. Lesion morphology, site of the lesion and presence of thrombus of the culprit artery and diameter and dominance of all coronary arteries did not differ between the well-conditioned men and control subjects. This study suggests that regular strenuous exercise can reduce coronary artery disease and shows a common pathogenesis for acute coronary syndromes related and unrelated to sport.

A dynamic migration model with uncertainty.

The author presents "a dynamic version of the Harris-Todaro migration model where a finite population of infinitely-lived Bayesian agents choose consumption and migration decision rules as a function of their histories. The agents do not know the production functions in the two sectors and learn about them through wage draws that they receive from the stochastic production functions. The government knows the true production functions but is uninformed about the agents' beliefs, and the actual wage draws they observe. The government maximizes its welfare function using wage subsidies in the two sectors, and a migration tax. We solve the agents' dynamics programming problem, and then use the solution to solve the government's dynamic programming problem. We study the effects of government policies on the population distribution, and illustrate the model by numerically solving a particular parametric example."

Retrieval of undeployed stents from the right coronary artery: report of two cases.

Two patients are described in whom an undeployed stent (1 Wiktor and 1 Palmaz-Schatz) was retained in the proximal segment of the right coronary artery during coronary angioplasty. In both cases the stent was caught by a technique using a second guidewire. The stent was removed in the first patient during bypass surgery; in the second patient it was removed from the femoral sheath.